(a) Field of the Invention
The present invention relates to a workpiece management system and a control method. More specifically, the present invention relates to a system for selectively managing workpieces used in the process of manufacturing semiconductor elements or thin film transistor liquid crystal displays (TFT-LCDs) and a method for controlling the same.
(b) Description of the Related Art
A conventional system and a method for selectively managing workpieces will first be described in the process of manufacturing TFT-LCDs.
A plurality of glass substrates i.e., workpieces in identical cassettes are transferred to equipment systems that respectively perform testing, repairing, cleaning, heating, and sealing processes, and are assembled into TFT-LCDs. The above noted processes that the glass substrates pass through are called a xe2x80x98job schedule.xe2x80x99
All the glass substrates in identical cassettes pass through the above mentioned equipment systems, although some glass substrates may pass through separate equipment systems. However, when a cassette is carried through the conventional TFT-LCD manufacturing processes, each piece of equipment receives a job schedule to handle all of the glass substrates in an individual cassette. Therefore, when glass substrates to be handled with at least two different job schedules are in the same cassette, these glass substrates cannot be handled with a single command. In the conventional system, it is impossible for an operator or host to select specific glass substrates and to assign different job schedules to each individual glass substrate.
Hence, when an operator attempts to selectively assign job schedules for individual glass substrates in a cassette in the conventional TFT-LCD manufacturing processes (either off-line or on-line), he must separately and manually operate each piece of equipment. However, it may not be appropriate for some types of equipment that requires continuous and detailed job instruction inputs such as particle measuring and/or monitoring devices.
It is an object of the present invention to provide a system and a control method in remote on-line manufacturing processes for selectively managing workpieces having different job schedules within an individual cassette without operator""s intervention.
In one aspect of the present invention, a system for selectively managing workpieces comprises equipment for receiving a cassette that has a plurality of workpieces and for performing a job on the workpieces, a database for maintaining job schedules on the workpieces and information on the cassette, and a controller for reading workpiece information and job schedule information from the database and controlling the equipment for the job when the cassette is loaded into the equipment, the workpiece information being to be performed on the equipment and the job schedule information being on a workpiece selected from among all the workpieces stored in the cassette.
The controller selects specified workpieces from among the workpieces stored in the cassette and controls the equipment so that the specified workpieces are processed with identical job schedules, and selects all the workpieces stored in the cassette and controls the equipment so that the workpieces are processed with at least two job schedules. The controller also selects specified workpieces stored on the cassette and controls the equipment so that the specified workpieces are processed with at least two job schedules.
The controller comprises an equipment server for controlling the equipment, and a host for transmitting workpiece information and job schedule information to the equipment server when a cassette is loaded into the equipment. Here, the workpiece information is executed on the equipment and the job schedule information is for a workpiece selected from all the workpieces stored on the cassette.
The host comprises a carrier manager for controlling an automatic transferring device so that a cassette is transferred between the plurality of equipment and stocker devices, a cassette manager for managing job status of the cassette carried by the automatic transferring device and a workpiece manager for managing job status and job schedules of a plurality of the workpieces stored on the cassette.
In another aspect of the present invention, a control method for selectively managing workpiece is provided, comprising the steps of reporting that a cassette that stores a plurality of workpieces is loaded into an equipment, referring to workpiece information on the database to be executed on the equipment and job schedule information on the selected workpiece from the workpieces stored in the cassette, and generating and transmitting a job start messages containing the above noted information and receiving the job start message, and selecting a workpiece stored on the cassette according to the information of the job start message, and handling the selected workpiece with the job schedule.
In the step of handling the selected workpiece with the job schedule, specified workpieces selected from the workpieces stored in the cassette, and specified workpieces are processes with identical job schedules, and all the workpieces stored on the cassette are selected and the selected workpieces are executed with a plurality of job schedules, and specified workpieces can be selected from among the workpieces stored on the cassette, and the specified workpieces are executed with a plurality of job schedules.